FIG. 14 shows a conventionally known surveillance recording and reproducing system having a frame switcher for switching video signals from a plurality of cameras for each frame for output and a recording-purpose VTR. Each video signal generated in a plurality of cameras CM1 to CMn (n is an integer more than 1) is selectively inputted to a recording signal output circuit 3 by a selection switch of a frame switcher 2. The recording signal output device 3 subjects the inputted video signal to signal processing such as continuity holding and modulation of an odd field, an even filed and a sub-carrier and the like to generate a recording signal, and records the recording signal on a magnetic tape 4.
The reproduction signal processor 5 reproduces the recording signal recorded on the magnetic tape 4, and subjects the reproduced recording signal to signal processing such as demodulation to reproduce a video signal. The reproduction signal processor 5 then inputs the reproduced video signal to memory 6 and a corrector 7. Memory 6 temporally holds the inputted video signal for one frame. When the present reproduction signal directly inputted from the reproduction signal processor 5 has an error, the corrector 7 uses a reproduction signal of the immediately preceding frame temporally held in memory 6 and corrects the error of the present reproduction signal to generate a corrected reproduction signal. The corrector 7 then inputs the corrected reproduction signal to a video signal output device 8. The video signal output device 8 converts the inputted corrected reproduction signal to a video signal according to a display device such as a monitor 9 and then inputs the video signal to the display device. The monitor 9 reproduces and displays an image by the inputted video signals.
In such surveillance recording and reproducing systems, when there is one camera, even if the reproduction signal reproduced and demodulated from the magnetic tape 4 by the reproduction signal processor 5 is replaced by reproduction signal information of the immediately preceding frame by the correcting means 7, their in-frame images therebetween has much correlation and therefore correction can be made without any problem. However, when there are a plurality of cameras, the video signals from each camera are recorded on the magnetic tape 4 and therefore the reproduction signals reproduced from the magnetic tape 4 by the reproduction signal processor 5 have video information different for each corresponding camera with much less correlation. Therefore, when the reproduction signal information of the immediately preceding frame is used in order to correct the reproduction signal with an error as described above, the video is disadvantageously replaced by the video information from a different camera without correlation, resulting in degradation in image quality after correction.
Therefore, an object of the present invention is to provide a video recording and reproducing apparatus capable of satisfactorily correcting an image of a reproduced image signal with an error even when video signals from a plurality of cameras are recorded.
Furthermore, FIG. 15 shows, as an example of conventional video recording and reproducing apparatuses, a surveillance recording and reproducing system, which is disclosed in JP-A-5-83632, having a frame switcher for switching video signals from a plurality of cameras CM1 to CMn for each frame for output and a recording-purpose VTR. Each video signal generated in the plurality of cameras CM1 to CMn (n is an integer more than 1) is selectively inputted to a recording signal output circuit 3 by a selection switch of a frame switcher 2. The recording signal output device 3 subjects the inputted video signal to signal processing such as continuity holding and modulation of an odd field, an even filed and a sub-carrier and the like and generates a recording signal which a video tape recorder 59 can record. The recording signal from the recording signal output device 3 is inputted to a superposition circuit 54, and a camera identifying signal representing a camera number is superimposed thereon in a vertical blanking period. The recording signal on which the camera identifying signal is superimposed is recorded by the video tape recorder 59. The camera number identifying signal superimposed on the signal reproduced from the video tape recorder 59 is detected by a reproduction signal processor 55. Based on the detected camera number identifying signal, a video signal only during a video period of an arbitrarily desired camera is identified and selected, and the video signals for one frame are temporally held in memory 56. At this time, the video signals of video signal periods of the other cameras are not recorded in memory 56, but only video signals of the same camera are read while being sequentially recorded in memory 56 and the video signals of the same camera outputted from a video signal output device 57 is displayed on a monitor 58. This allows selection and playback of only the video of the arbitrary camera.
In the video recording and reproducing apparatus structured as described above, if the video tape of the video tape recorder 59 runs at normal single speed during playback, it is possible to detect the camera number identifying signal superimposed on the video signal reproduced from the video tape recorder 59 and inputted to an identifying device 55. Therefore, images recorded by a desired camera can be selected and watched among images recorded by the plurality of cameras. However, since the camera number identifying signal is superimposed in the vertical blanking period, it is difficult to accurately detect the camera number identifying signal during high-speed replay where a magnetic tape speed is made high for fast-forward or in reverse. As a result, high-speed replay of only the images from the desired camera number is very difficult, and actually, impossible.
Furthermore, even when there is one camera, since the tape is controlled only at a desired speed during high-speed replay at more than single speed, uniform playback of the recorded video from the camera is very difficult and actually impossible.
Therefore, an object of the present invention is to provide a video recording and reproducing apparatus capable of high-speed replay of only recorded video by a desired camera even when video signals by a plurality of cameras are recorded, uniform high-speed replay of the recorded video of the camera, and further satisfactorily correcting an image even when a reproduced image signal has an error.